June 12, 2010

In this article, I will talk about how to control IO ports using Embedded Linux platforms.

The platform which is used in this project is a edb9302 compliant development board. It has 16 MB Intel strata flash and 32 MB SD RAM, gpio connection in order to communicate custom design interfaces, for information about the development board, can be looked at this link;

http://www.cirrus.com/en/products/pro/detail/P1066.html

Briefly in this project , i have connected a elt240320atp LCD screen to the embedded Linux development board with a parallel gpio interface.

An interface software is written, in order to create communication between the embedded Linux development board and the elt240320atp LCD screen.

Let’s take a look interface software.

The program is designed to communicate with lcd screen can be split into two parts, gpio controller and elt240320atp lcd screen controller.

All right, how to open GPIO interface without using a device driver in a Embedded Linux platform?
Answer, using /dev/mem device.

/dev/mem device is a king of character device is used to access to physical memory via generic file manipulation system calls, for example; open, read, write, seek, close, etc.